© 2019 by Andy Pilgrim

On the limit and beyond

August 20, 2009

Laguna Seca is one of my favorite tracks in the US and this past weekend proved again how much of a great race track it really is.  

Anyone who caught the last run to the checkered flag during the ALSM race, between Jan Magnussen in his Corvette and Jorg Bergmeister in his Porsche, will have no doubts about it.  The Corvette and Porsche banged and bumped and finally crashed their way to an amazing finish.   That finish prompted me to talk about limits in this article, finding the limit, riding the limit and how sometimes we go over the limit.  

Ok, I’m only talking about racing stuff here, not spending limits or eating limits as SpeedTV.com only gives me 1800ish words here, not a book.   

Unlike our last race in Atlanta, the rain issue did not raise its ugly head in any forecasting during our few days in the beautiful Seaside, CA area.  Every day it was pretty cold and cloudy as far as I was concerned but my Denver crew mostly passed it off as “fresh,” whatever that’s supposed to mean.

As drivers, any time we are on a race track, whether for a track day, a club race, a National race or a Pro race, we look for limits.  The car has limits and we have limits.  I had my own battle with limits on the track this weekend and almost got caught up in other people’s battles with them.  Let me enlighten you a little.

Thursday was promoter test day.  This is a day when we run two 30-minute sessions as practice only and the SCCA is not involved in timing or policing pit lane etc. 
 
We use this as a great day to find the direction on set-up for the weekend.  This particular weekend Randy Pobst, my teammate on the K-Pax/3R team, had a different suspension and drive line set up on his Volvo S60 AWD.  This is not unusual for a two-car team.  Having the cars set up different means we can more quickly get a good direction on where to go.

In the first session it became obvious Randy loved his car and mine was, to say the least, not exactly perfect. In fact, it was extremely nervous on corner exit and not consistent from one lap to the next.  My job as a driver is to give as accurate feedback as possible to my engineer; then he has a chance to fix it or make it better.  

During down-loading to my engineer, it became obvious that the car was possibly bi-polar or, more likely, had some set-up issue in the suspension or drive line or both.  I have a great crew and between them and the engineer, they decided to not change too much and get a better hold on what exactly might be the issue.

Let me give you the low-down on what I was dealing with.  I was having an inconsistent, increasing yaw on power-down, post-apex to exit of the corner. Oh well, great, thanks for sharing Andy.  OK, bottom line is this, the back of the car wanted to come around as I added gas to exit the corner but it was doing so inconsistently. 
 
This in itself is not a problem for a rear-wheel drive car or unusual, necessarily But for an All-Wheel Drive car this was very unusual and something we had not experienced this year.  My job was to try and isolate whether it was a driveline issue with our center diff and front to rear gear ratio, or a chassis problem.  So, off I went for the second session of the day in search of the Holy Grail, an answer to things unknown.

In order to really analyze the car I have to be on the limit.  Now normally this is comfortable and I can get an idea of feedback quickly and we can move on.  In this case the car was not consistent from corner to corner and lap to lap, which made it difficult and unusual. 
 
I knew the car was tricky, we had talked about it in debriefing and we were going through the motions to change it or correct it while all the time understanding the car was being a pain and nervous.  After being out for an initial three laps, I reported in that the condition was about the same, despite changes made to the chassis.  My engineer made a change to the rear anti roll bar and off I went again for a few laps to get another idea, just to see if this made things better.  Well, it did initially make it better on power down, but, late in corner exit the softer setting allowed the car to roll over more and it became even more tail-happy.

I had a big slide through turn 2 and suddenly figured out that the turbo boost was possibly having an effect on the slide late in the corner as full boost came in.  We have a big turbo on a small motor and it takes more than a second to make full boost.  

As I drove from turn 2 to 3, which takes about 3 seconds, I was thinking to myself, the problem might be the drive line ratio split between the front and rear and NOT chassis.  The ratio was possibly transferring power to the rear more quickly than the chassis and tires could handle as the boost kicks up to full power.  Ok I’ll try and get more ideas out of turn 3, I say to myself.  Sure enough, as I exit the very tight turn 3 the car rolls - due to the softer bar - then again throws the rear out on full power, but the two happened so closely that I could not quite isolate chassis roll from drive line.  

Ok off to turn 4 - an 85 mph constant radius longer turn and should give me more time to analyze what exactly is going on.  In I go, back to constant gas as fast as I can, then squeeze the gas, out comes the rear, ok, that was chassis I thought to myself.  Then, in comes the boost and man the rear just said SEE YA!!!! 

The rear of the car came around so fast that it surprised me. I turned into the skid and then, oh great!  I didn’t say “oh great” to myself. 

I had reached the limit of steering lock.  We have very little steering lock on our Volvo race car due to the front drive axles.  The rear just kept coming around and there was no steering lock left to do anything about it.  

As I slid wide on the exit, I dropped my left rear into the dirt due to the slide. This further accelerated the rotation of the rear.  I was off the throttle, jerked out of my thinking-about-set-up while-driving mode, and back into the real world of oh, crap!  

The car was sliding sideways down the race track on full steering lock and not even thinking about going straight.  As I pumped the brake to make anything change the aspect of the car, it finally started to straighten out, but too late.  The front right corner caught the tires at about 60 mph.  Practice over!

Fortunately, the car was only superficially damaged, but this still took my 3R crew seven hours to fix it.  The crash had crushed a bunch of thin metal on the unibody, metal they had to beat out and re weld in order to hang body pieces back on the front.  They did a beautiful job of it.  Thank goodness the suspension and chassis was untouched and the right front corner took all the force.
The crash had happened because I let my head get just fractionally out of the ‘now’ and into trying to analyze whether the problem with the car was chassis or drive line ratio. Totally my fault.  
True, if I had more steering lock I would have been fine. But I know the car has limited lock, so again, my fault.  My hat’s-off to my crew who did a masterful job of fixing the car. I was ready to go the next morning, missing no track time at all.

The moral to me is:  When you’re on the limit of the car, make sure other thoughts stay in background until you’re out of the corner or in the pits and chatting with your engineer, especially when it’s something inconsistent or as tricky as this was.

So, with that mess cleared up, off we went for the next official practice sessions on Friday, still trying to figure exactly what was up.  Randy was liking his car for the most part and he was chasing track condition changes more than car quirks. 

We did all we could to help the chassis on Friday but all data was pointing to a drive line ratio issue that pushed too much drive to the rear tires when on gas and even more as boost built up.  We needed to make our ratio the same as Randy’s car. Unfortunately we didn’t have the parts to change it at Laguna. 

No worries, I was just happy to know we found the issue and could calm it down, even if we couldn’t fix it.  We changed the car dramatically for qualifying, then again for the race to try and help things out. These are not normal things to do before qualifying and race as far as set up changes but, sometimes, them’s the things ya gotta deal with.

I ended up qualifying 11th and Randy got 6th. Not too bad, considering. 
 
I think the SPEED World Challenge series is in pretty good shape these days; we had 21 cars entered for this final race.  A great car count considering the economic situation.
The race itself was a wild one.  James Sofronas in his GMG Porsche GT3 basically dominated from flag to flag, so congratulations to him.  My teammate Randy Pobst finished second with Eric Curran in his Whelan Engineering Corvette coming in 3rd.  I ended up 5th and was plenty happy with that.
I had a wild race, three times nearly getting caught in other peoples nightmares (stuff happening in front of me or at the side of me, in other words) which should make for some fun TV footage.  
Brandon Davis won the SPEED World Challenge GT Championship for the year and Pierre Kleinubing won the championship in Touring Car -- excellent job by both of them and their teams.
The Brass Monkey Racing boys won Crew of The Year for taking Tony Rivera and his Porsche 911 GT3 to an excellent third place in the Drivers’ Championship.  On a personal note I want to say “great job” to Tony. We had some very tight and close races; he did a stellar job all year and I hope we get to run against each other again next year.

I was presented with the Jim Cook Award for 2009.  This means a great deal to me and I want to thank SCCA and all the other people involved in the selection process.  The trophy is awarded to someone in pro racing who does something to show pro racing in a good light or enhances the image of pro racing.  My work with teen drivers was a key to my receiving the award for which I am very proud.

It looks like K-Pax/3R will be back next year.  We have come a long way in our first year with the Volvo S60 AWD and I look forward to seeing all of you race fans again in 2010.  
Take care all, and have a great holiday season.

 

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